A5055586971- Magnetic Properties and Applications
- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
- Magnetic Properties of Alloys
- Microstructure and Mechanical Properties of Steels
- Shape Memory Alloy Transformations
- Characterization and Applications of Magnetic Nanoparticles
- Micro and Nano Robotics
- Multiferroics and related materials
- Microfluidic and Bio-sensing Technologies
- Magnetic and Electromagnetic Effects
- Heusler alloys: electronic and magnetic properties
- Ferroelectric and Piezoelectric Materials
- Non-Destructive Testing Techniques
- Advanced Cellulose Research Studies
- Intermetallics and Advanced Alloy Properties
- Advanced Antenna and Metasurface Technologies
- Physics of Superconductivity and Magnetism
- Modular Robots and Swarm Intelligence
- Microwave Engineering and Waveguides
- Antenna Design and Analysis
- Rare-earth and actinide compounds
- Metallic Glasses and Amorphous Alloys
- Advanced Memory and Neural Computing
- Electric Motor Design and Analysis
United States Naval Academy
2015-2023
European Synchrotron Radiation Facility
2020
United States Naval Research Laboratory
2020
University of Liverpool
2020
X-Fab (Germany)
2018
George Washington University
2012-2015
Cairo University
2012
University of the District of Columbia
2012
The phenomenon of negative remanent magnetization (NRM) has been observed experimentally in a number heterogeneous magnetic systems and considered anomalous. existence NRM homogenous materials is still debate, mainly due to the lack compelling support from experimental data convincing theoretical explanation for its thermodynamic validation. Here we resolve long-existing controversy by presenting evidence physical justification that real prototype homogeneous ferromagnetic nanoparticle, an...
Abstract Flexible intracortical neural probes have drawn attention for their enhanced longevity in high-resolution recordings due to reduced tissue reaction. However, the conventional monolithic fabrication approach has met significant challenges in: (i) scaling number of recording sites electrophysiology; (ii) integrating other physiological sensing and modulation; (iii) configuring into three-dimensional (3D) shapes multi-sided electrode arrays. We report an innovative self-assembly...
Combining and coupling both magnetic electric properties in one single phase multiferroic material has attracted high interest recently to enable a broad range of novel devices applications. To evaluate potential route toward new multiferroics, we have studied 0.5% Fe-doped BaTiO3 crystals measured the ferroelectric, magnetic, properties. X-ray absorption spectroscopy shows presence Fe3+, measurements confirmed that this significant impact on Doping iron introduces paramagnetism from lone...
The adiabatic temperature change (ΔT) during the magnetization and demagnetization processes of bulk gadolinium is directly measured for several applied magnetic fields in range 285 K to 305 K. During process, ΔT measurements display same maximum each field when plotted against initial (Ti). However, varies field. This discrepancy between appears inconsistent with reversibility magnetocaloric effect. A new approach undertaken highlight effect by plotting average (Tavg) instead Ti. value Tavg...
The magnetocaloric temperature change (ΔT <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Temp</sub> ) is an important factor in the performance evaluation of material's effect (MCE), which has been attracting significant interest due to its application energy efficient near-room magnetic refrigeration technology with environmentally desirable characteristics. A novel test system fully controlled field, temperature, and time capabilities...
The magnetic susceptibility of pyrolytic graphite (PyG) is temperature dependent. Under an external field, a levitated PyG sample with localized change experiences unequal diamagnetic forces. In this paper, we present study the macroscale optomechanical displacement by using laser source to locally increase temperature. Dynamic finite-element method simulations show that in temperature, simulating source, decreases force local area, leading plane permanent magnet array. Experimental setups...
The NiMnInSi Heusler alloy family is analyzed, and a self-similarity based method used to analyze the first-order transition of Ni-Mn alloys. This appropriate determine magnetic characteristics Magnetocaloric Effect providing that there sufficient separation in their phase temperatures. A temperature scaling methodology model cluster compositions mixed-state regions where two stable states co-exist. various descriptions classifications these transitions, however, are not critical this analysis.
This describes the application of a visual servo control method to microrobotic manipulation polymer beads on two-dimensional fluid interface. A microrobot, actuated through magnetic fields, is utilized manipulate non-magnetic bead into desired position. The controller utilizes multiple modes robot actuation address different stages task. filtering strategy employed in separation mode allows spiral from manipuland fashion that promotes positioning objective. Experiments demonstrate our...
The latent heat linked with the first-order transformation of a NiMnIn Heusler alloy has been studied through direct measurements adiabatic temperature change, ΔTad, during magnetization process. experimental procedure used guarantees independent data points and negates any contribution hysteretic losses to magnetocaloric effect. Thus, differences between magnitudes ΔTad initial change directions from low-to-high high-to-low are solely attributed exchange, which accompanies irreversible...
Live-line maintenance workers (linemen) are exposed to very high magnetic flux densities due the nature of their work, which requires working in close proximity transmission lines. Although evidence adverse health risks remains non conclusive and debatable date, it is still sufficient warrant limited concern according international standards. The research presented this paper aims provide numerical comparative assessment risk exposure linemen on power lines three different voltage levels...
A model for the magnetostriction of high-strength steels under uniaxial compressive stresses is presented to simulate experimental measurements. previous Preisach-type modified Villari reversal phenomenon. The can also account crystallographic anisotropy which arises from stress magnitude as well machining process sample. net axial sample modeled by a Preisach-type, two-component model. first component corresponds steep rise in initial stage followed rotation magnetic domains direction...
Purpose Demonstrating multifield and inverse contrast switching of magnetocaloric high ratio MRI labels that either have increasing or decreasing moment versus temperature slopes depending on the material at physiological temperatures different magnetic field strengths. Methods Two iron‐rhodium samples purity (99% 99.9%) a lanthanum‐iron‐silicon sample were obtained from commercial vendors. Temperature field‐dependent measurements performed vibrating magnetometer. Temperature‐dependent 3...
A numerical implementation of the classical Stoner-Wohlfarth (SW) model to simulate magnetization angle an assembly SW particles with effective axis anisotropy under a rotating applied field is presented. Using angular distribution for each particle making medium's reference axis, proposed successfully simulated lag-angle plots exhibiting same rotational behavior measured different ellipsoidally magnetizable media in literature. The developed algorithm provides simple tool...
When levitating above an alternating-pole permanent magnet array, pyrolytic graphite can be displaced by asymmetric diamagnetic forces resulting from optically-induced, localized temperature changes and the thermal dependence of graphite’s magnetic susceptibility. In this paper, we present methods for addressable, automated position control samples acting as milli-robots small-scale assembly manipulation applications using optical actuation machine vision techniques. A simple method is...
The metastability of the nonstoichiometric Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">51</sub> Mn xmlns:xlink="http://www.w3.org/1999/xlink">33.4</sub> In xmlns:xlink="http://www.w3.org/1999/xlink">15.6</sub> Heusler alloy in first-order transition region is studied using direct adiabatic temperature change (ΔT xmlns:xlink="http://www.w3.org/1999/xlink">ad</sub> ) measurements for heating and cooling magnetization processes. During...
In this work, metallic silver nanoparticles were synthesized in linen powders by the process of incipient wetness impregnation. Linen with varying concentrations particles prepared control amount nitrate added during synthesis. These composite materials characterized XPS, SEM, EDS, ATR-IR, and Raman. XPS showed that was predominately zero valent. SEM did not show any distinct at limit instrument resolution. However, EDX indicated a uniform distribution all powders. The ATR-IR exhibited no...
The significant diamagnetism of pyrolytic graphite (PyG) allows it to be passively levitated above permanent magnet arrays and translated in the plane these via optical irradiation, which promotes applications frictionless milli-scale robotics. Previous explanations for translation effect have cited photothermal heating PyG thermal dependence PyG’s magnetic susceptibility, as observed through measurements samples at uniform temperatures. In this article, we offer a revision theory actuation...
Even though Isaak Mayergoyz described it as: “much more accurate for the description of superconducting hysteresis than magnetic materials”, Preisach modeling is not a popular investigative tool. This might be due to complexity identifying distribution function or lack convincing physical reasoning behind pure phenomenological versions. In this paper, two-component Preisach-type model presented which computationally-efficient and physically-sound. The change in slope minor loops incorporated...
A model for the vector magnetization of a distribution uniaxial particles is presented. Recent work by authors decomposed into two components and modeled total as their sum. Anisotropy could be ideally constant field, but this leads to unidirectional anisotropy. Considering media, such approach will only valid small angles. Hence, in paper, proposed that calculates sum irreversible reversible components. The magnitude component using Preisach differential-equation approach; however, other...
We model and analyze the effect of particle shape on signal amplification in inductive coil magnetic resonance detection using reversible transverse susceptibility oriented nanostructures. Utilizing single domain Stoner-Wohlfarth uniform magnetization rotation, we reveal that different ellipsoidal shapes can have a pronounced flux enhancement configurations typical settings. compare contrast prolate ellipsoids, oblate exchange-biased spheres show ellipsoids significantly higher than...